J. Zhang et Sj. Vanenk, EXCESS PHOTON IONIZATION AND HARMONIC-GENERATION THROUGH AN AUTOIONIZING RESONANCE, Physical review. A, 52(6), 1995, pp. 4640-4646
We analyze above-threshold ionization through an autoionizing resonanc
e and show that this process is strongly enhanced when the photon is t
uned near the minimum of the primary photoionization peak; the enhance
ment occurs also when the free-free transitions are taken into account
. We demonstrate that this property can be exploited to enhance the ha
rmonic generation.